Bag for a beverage preparation

ABSTRACT

In the interior of a disposable closed bag formed of a package material, a beverage preparation of a solid substance is placed, the substance being capable of giving off components of the beverage through the water-permeable packaging material when the bag is infused in water for preparing the beverage. On part of the package material the bag includes a supporting surface which is formed as a water-impermeable structure having an upward dimension as a collar of a given height, for preventing water from leaking out from the wetted beverage preparation in the bag.

BACKGROUND

The present disclosure relates to a bag for a beverage preparation as presented in the preamble of the appended claim.

A beverage preparation in the form of solid raw material for a beverage to be prepared by brewing or extracting is packed in a water-permeable bag (filter bag) in order to prevent this material from being mixed with the beverage. The filter bag, in turn, can be packed in package material enclosing the bag and forming a single protective package for the filter bag. Such protective packages may be packed in a larger box-like sales package. The most common examples of such packages are packages of tea beverages to be prepared by brewing or extracting, that is, packages of tea bags. A conventional rectangular flat protective package, to which the string of the tea bag is also fastened, is disclosed, for example, in U.S. Pat. No. 3,175,911.When using a bag containing raw material for a beverage and made of a suitable filter material, it is placed in a cup into which hot water is poured or which already contains hot water, after which the bag is infused in the water as long as the components of the beverage dissolve from the raw material contained in the filter bag to a desired concentration in the water in the cup.

Problems with such packages are caused by the fact that the raw material inside the filter bag becomes wet and swells when it is infused. When the bag is taken out of the cup, it messes up places. If one wants to drain remaining liquid into the cup by squeezing the bag, this is difficult with-out staining one's hands, if no appliances are used. Even if the bag had been made dryer by squeezing, some liquid is always left in it, dribbling from the bag onto the surface on which the bag is placed.

A number of patent documents disclose solutions to overcome these problems. A very common approach to overcome the problem is to make the package of the bag in a way “openable at the bottom”, so that the bag can be lowered into a cup while carried by a string, and lifted by the string back into the package again, wherein the package can be used to squeeze the bag without staining one's fingers, and for holding the bag, as is disclosed, for example, in international publication WO 96/01773. However, it is difficult to pull the swollen bag into the package, if the package is dimensioned to fit closely the dimensions of the dry bag. Furthermore, liquid can still run through the opened bottom of the package, if the package, after the use, is placed in a horizontal position on a table.

Furthermore, tea bags are known, in which the suspension string has been guided in such a way that the bag can be squeezed dry by pulling the string. This requires special guiding arrangements of the string and a special attachment to the bag in order to obtain a loop for squeezing the bag dry, as disclosed, for example, in US 2004/071830.

International publication WO 98/04460 discloses a tea bag which can be drained by tilting the bag to an angle of about 45 degrees, wherein the bag and the vertical edge form a downwards directed “tip”, above which water accumulates and forms a kind of a bed which generates a pressure removing water more efficiently from the bag. According to the embodiment shown in FIGS. 3A and 3B, the draining position is obtained by fastening one end of the string off the centre (the centre line of symmetry of the bag), so that the bag can be suspended in a slanted position.

Furthermore, elongated bags are known, which can be used as stirring sticks so that when water is being stirred, the material contained in the bag simultaneously dissolves in water through a porous wall. For example document US 2002/0162461 discloses the use of densely spaced micropores (smaller than 0.5 to 0.35 mm) in a bag material, whereby the effect of surface tension is reduced and water can enter the bag and the substances dissolved in water can come out of the bag by diffusion. The bag can be used for preparing beverages from a water-soluble or extractable material.

When micropores are used, it is probably possible to reduce the leaking of water from the bag after the use, but contact with a surface may trigger dribbling of water out of the bag. When such a bag is used for extractable powdery beverage preparations (such as tea leaves), water cannot flow properly through the powder and “flush” it, which is essential in order to release flavouring agents into water as well as possible. So that the bag could be used for stirring in the initial step, the powder has to be packed sufficiently densely into the bag, but when it becomes wet, the powder will swell and impair the absorption of the substances.

For the above-mentioned reasons, particularly powder preparations, from which substances are to be extracted into water, are packed into gauze bags which have a large open surface area and are thin so that water can flow into and out of the bag and flush the powder which is packed loosely in relation to the volume of the bag. This is exactly how tea leaves are packed. If one does not want to squeeze the bag dry, either with fingers or with special appliances, the only alternative for squeezing dry is then to drain water out of the bag, for example in the slanted position presented in WO 98/04460.

It can be shown by experiments that after water has been drained by shaking sufficiently long (for 2 to 3 seconds) out of a relatively open-surfaced bag that has been infused in water, drops no longer appear although the bag contains a lot of water. This is because the rest of the water is retained by the absorbency of the powder and by the surface tension of the water. However, when the surface of such a bag is touched, more water will come out exactly from the point of contact; in other words, the cohesive surface tension of the water is broken at the point of contact. The same phenomenon occurs when a seemingly non-dripping bag is placed onto a solid surface, creating a contact with the water in the bag.

All in all, the problem involved in all bags is thus the fact that to make sure that no water can come out of the bag after the use and possible draining by dripping, the user has to place the bag that has been infused in water onto a special tray or into the package, to avoid staining of the table.

SUMMARY

It is an aim of the present disclosure to eliminate the above mentioned drawbacks and to present a disposable bag for a beverage preparation, which does not require separate trays or squeezing devices, but it can be, after the infusion, placed as such on a table or in another place which is to be kept clean. To attain this aim, the bag according to the aspects of the present disclosure is primarily characterized in what will be presented in the characterizing part of the appended claim 1.

The bag comprises a supporting surface formed as a structure that is impermeable to water. This supporting surface comes against the counter surface, onto which the wet bag is placed after the infusion. The supporting surface provides the bag with supporting points which support the bag so that it will remain in a position where the supporting surface is lowermost against the counter surface. The water-impermeable structure of the supporting surface extends upwards (above the supporting points) as a collar of a given height, encircling the whole bag in the horizontal direction and preventing the dribbling of water out of the bag from the lowermost point of the wet beverage preparation straight in the horizontal direction. The water-impermeable structure is an integral part of the package material of the bag (the wrapping material enclosing the beverage preparation) which, in other parts, remains permeable to water, that is, has a filter structure. In one alternative, the bottom portion of a vertical bag (that is, a bag whose height is greater than the largest dimension of the bag in a direction transverse to the height) or the bottom portion of a polyhedral bag is formed as a water-impermeable structure, above which the side wall of the bag extending in the height direction is permeable to water (having a filter structure) for infusing a beverage preparation contained in the bag, so that its components would dissolve in water. The water-impermeable zone of the bottom portion extends to a suitable height in the direction of the side wall of the bag, forming the above-described collar which extends to a given height and encircles the supporting plane formed by the bottom. Such a bag may be a bag made by folding and seaming of the package material of the bag, for example having the general shape of a conventional tea bag or the shape of a tetrahedron or another polyhedron. After the bag infused in water is placed upright on a table or another counter surface, the water tending to leak out from the beverage preparation will remain in a kind of a “trough” inside the bottom portion which is impermeable to water.

The water-impermeable bottom portion can be provided, for example, at the bottom of a beverage preparation bag having the shape of an ordinary tea bag, or at the bottom face of a bag having the shape of a tetrahedron or another polyhedron, and to encircle the bottom. It thus covers a small part of the surface area of the wrapping material of the bag and does not impair the infusing efficiency. It is thus possible that said bottom portion is the area covering one face of the polyhedral bag, to be laid lowermost against the counter surface, and the area extending from the face in the height direction to the lower part of the other faces, or the area covering the bottom of the bag having the shape of an ordinary upright tea bag and the area extending from the bottom in the height direction to the lower part of the upright side wall. It is also possible that the water-impermeable structure extends in a large supporting surface in the bag, for example on one large side of a flat bag. The bag is thus placed in a horizontal position, with the supporting surface against the counter surface. In this alternative, the surface area available for infusing is smaller.

So that the dissolving of components from the bag into water and the draining of water from the bag thereafter could be controlled better, the bag comprises two suspension points which determine two different inclination positions for the bag when the mass centre of the bag is placed by gravity below the suspension point: a setting position, in which the bag is hanging with the water-impermeable supporting surface facing downwards, and a draining position, in which the supporting surface is turned to an angle with respect to the setting position. For example in the draining position of an upright bag, the side wall of the bag above the water-impermeable bottom portion is turned to a smaller angle with respect to the horizontal plane than in the setting position, and the lower surface of the bottom portion is correspondingly inclined to the side, that is, the bag is in an inclined position. In this draining position, in which the bag can be inclined or horizontal, or even with its upper end down, water can be drained more easily from the bag after the infusion through the water-permeable package material. When allowed by the inner dimensions of a cup or a glass, this position can also be used as the infusing position, wherein the beverage preparation contained in the bag comes better in contact with the water in the cup or glass, when the solid beverage preparation accumulates onto the water-permeable side wall, the water flushes the beverage preparation contained in the bag, and the components of the preparation dissolve better in water. When the bag infused in this position is lifted off the water, it can be drained dry in the same position. A bag infused in another position in water can also be lifted off the cup or glass and turned to the draining position.

The setting position and the draining position obtained with the different suspension points can be utilized in all bags, irrespective of their general shape. Thus, in the setting position the supporting surface is located lowermost towards the counter surface, and in the draining position the supporting surface is turned to another position and the water-permeable area in the package material is turned more towards the horizontal plane.

When the bag is turned from the draining position to the setting position, the beverage preparation contained in it will be packed on top of the water-tight bottom portion again and will not cause problems of leaking when the bag is set with the water-impermeable supporting surface against a table or another counter surface. Water possibly leaking from the wetted beverage preparation will remain on top of the water-impermeable structure and does not leak to the sides, because the water-impermeable structure also has an upward dimension in the form of a collar.

The suspension point of the setting position is in the bag on the side opposite to the supporting surface, and the suspension point of the draining position is closer to the supporting surface of the bag with respect to the above-mentioned point, for example in the side wall or in the bottom part in an upright bag. Preferably, the supporting point is placed in the water-impermeable structure of the bag.

In practice, the suspension points which support the bag against gravity can be fastening points of a suspension string. It is possible to use, for example, one suspension string which forms a loop between the fastening points. This also makes it possible to adjust the angle of the draining position of the bag precisely by exerting a supporting force on both suspension points simultaneously, and the bag can also be infused precisely in a desired position which can be different form the setting position and the draining position.

The bag itself is a disposable bag, inside which the solid beverage preparation is enclosed by sealing the enclosing package material in such a way that the bag can only be opened by tearing the package material or by opening a seam which has been formed by sealing the edges of the package material together, or by opening a seam of different kind which has been formed by sealing the package material permanently by means of a rivet, a self-adhesive label, a knot of a binding material, or another corresponding closing member. The bag can be made of a blank comprising a water-permeable area and a water-tight area by folding and seaming to form a closed structure, whose lower portion is provided with a water-impermeable structure consisting of the water-tight area of the blank. The bag is simultaneously formed to have a structure with a sufficiently large supporting surface so that the bag will remain in the setting position. The upright bag can be made in such a way that the bottom surface of the lower portion is sufficiently large and supports the bag in the upright position.

The blank can be implemented as a combination of the water-permeable area (the area having the filter structure) and the water-tight area by covering the blank, which originally consists wholly of the material having the filter structure, partly with a film of a water-tight material, wherein the water-permeable area will remain outside the area covered by the water-tight material; or by starting from a blank originally consisting of a water-tight material and by modifying the material in such a way that a water-permeable area is formed on part of the surface area of the blank, outside which an unmodified area of water-tight material is left. The water-permeable area can be modified in the blank material, for example, by perforating with a given hole density and hole size, whose combined effect provides a sufficiently open surface area. It is also possible to modify a material which normally has a filter structure, for desired parts to become impermeable to water, for example by a coating technique, without needing to attach a separate impermeable finished piece of a material film onto the filter structure material.

The tight material film may be fastened to the package material throughout or pointwise.

The blanks may be provided one after the other as a blank web, from which blanks of a given size are separated, folded, filled in a suitable step with a solid beverage preparation, and finally sealed to form closed bags.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the aspects of the present disclosure will be described in more detail with reference to the appended drawings, in which:

FIG. 1 shows a bag according to the invention in a general view,

FIG. 2 shows the bag in the infusing position/draining position in a front view,

FIG. 3 shows the bag in the setting position in a front view,

FIG. 4 shows a blank web for making a bag according to FIGS. 1 to 3,

FIG. 5 shows another blank web,

FIG. 6 shows a bag made of a blank from the blank web of FIG. 5, and

FIG. 7 illustrates how the invention can be applied in a bag of any shape.

DETAILED DESCRIPTION

The filter preparation is packed in a filter bag 1 consisting primarily of a material that is permeable to water. The beverage preparation is in solid state, for example powder or granules or various vegetable parts, from which a beverage can be prepared by infusing the bag 1 in water for a suitable time, wherein the components of the beverage dissolve from it in the water. The process is often called infusion. Tea and various spiced teas and herbal teas are one example, but the invention is not limited solely to bags containing the raw materials for such beverages.

The bag 1 can have the general shape of a conventional flat filter bag 1 or a polyhedral bag (for example a tetrahedral bag, “pyramid bag”) which has recently become more common. It can be made and filled by automated apparatuses of prior art starting from a bag blank which has been provided in advance with a water-impermeable i.e. water-tight area on part of its surface.

The bag 1 is a disposable closed bag formed by folding and seaming of a suitable package material (wrapping material), inside which the beverage preparation is packed when the bag is partly open in the forming step. The beverage preparation is packed in such a way that it only fills a part of the inner volume of the bag (the degree of filling is only half or even less than half calculated on the basis of the volume of the freely settled preparation). This improves the dissolution of the components from the beverage preparation. The bag of FIG. 1 is an upright bag with the shape of a conventional tea bag. The bottom portion 3 of the bag is a structure 1 b which is impermeable to water from the lowermost bottom to a given height. The structure 1 b has an upward dimension; in other words, it has a collar that is impermeable to water and extends to a given height. The water-impermeable structure 1 b is an area impermeable to water and arranged on part of the surface area of the package material, placed in such a way in the package material that in the finished bag it also constitutes a water-impermeable collar extending to a given height above the horizontal plane determined by the supporting points of the bottom of the bag, to prevent leaking of the liquid. Above the water-impermeable collar of the bottom part 3, the bag extends directly as side walls 2 formed of a water-permeable area 1 a having a filter structure. The figure also shows two suspension points: a suspension point A corresponding to the setting position, and a suspension point B corresponding to the draining position. The suspension point A corresponding to the setting position is located at the upper end 2 a of the bag, on a centre line of symmetry C; in other words, when the bag is supported from this point, the bag is hanging with the bottom portion 3 facing downwards. The suspension point B corresponding to the infusing position/draining position is placed off the said point so that when the bag is supported from this point, the side wall 2 of the bag located in the area 1 a having the filter structure is turned to a smaller angle to the horizontal plane than in the setting position. This angle can be for example 0, wherein the side wall is approximately horizontal. The angle can also be negative, wherein the side wall is directed diagonally downwards. In FIG. 1, the suspension point B of the infusing position/draining position is at the edge of the water-tight bottom portion 3.

In the case of a flat bag shown in FIGS. 1 to 3, where the water-permeable side wall (having the filter structure) comprises wide front and rear walls which approach each other in a wedge-like manner and upwards, and are joined at the upper end 2 a of the bag, the infusing position/draining position is arranged in such a way that the side edge 2 b of the front wall and the rear wall (the point where there is a fold in the area 2 having the filter structure) is tilted so that its angle to the horizontal plane is reduced when the bag is supported from the suspension point B. This side edge is in the setting position (FIG. 3) approximately upright when the bag is viewed directly from the front (angle about 90°), and it is tilted to approximately the horizontal plane (angle 0) in the infusing/draining position (FIG. 2). The fold at the side edge 2 b of the front wall and the rear wall thus forms a wedge inside the bag, guiding water to drop via the edge and its vicinity through the material having the filter structure, when water is drained from the bag into a cup. To achieve this, the suspension point B of the infusing position/draining position is placed at the other edge of the bag, so that the opposite side edge 2 b of the bag can be directed downwards in the infusing position and the draining position. The suspension point B can be placed, for example, at the edge of the bottom portion 3, which is between the front wall and the rear wall.

The suspension points A, B can be marked or determined in the bag in a suitable way. They can be, for example, holes or loops, at which the bag can be gripped and suspended. Advantageously, the suspension points A, B are connected with a suspension string 4; in other words, they are fastening points of the same suspension string. Thus, by means of the suspension string, the angular position of the side wall of the bag having the filter structure can also be adjusted by holding the suspension string 4 at a suitable point.

FIG. 2 shows the infusing position and the dripping position, in which the bag can be held in water and drained drier. In this position, water in a cup or a glass can easily penetrate into the bag and dissolve components of the beverage from it. When the bag is lifted up from the water and held in the same position and possibly shaken, excessive water can drop through the water-permeable side wall of the bag back to the cup or glass.

The bag shown in FIG. 3 is in a setting position, in which the water-tight bottom portion 3 is lowermost, and the bag from which excessive water has been drained off can be placed against a counter surface 5, for example a table. Thus, the bottom of the water-tight bottom portion 3 serves as a supporting surface that comes against the table. In this position, the bottom portion 3 prevents water from leaking from the beverage preparation inside the bag. The water-tight bottom part also prevents a direct contact between the surface and the wetted beverage preparation, which could cause seepage of water onto the surface.

The bag of FIG. 1 has the general shape of a bag similar to an ordinary tea bag, which has been formed by folding double an intermediate form having the shape of a flat hose which, in turn, has been made by wrapping from a planar blank in such a way that the seam formed by overlapping edges of the blank is left in the centre of one of the flat surfaces of the hose, which in the hose folded double is left inside, the opposite flat surface forming the outermost front surface and rear surface (front wall and rear wall) of the tea bag. The ends of the hose are joined together and they form the upper end 2 a of the bag. Transversely in the middle of the hose, there is a zone of an area 1 b which is impermeable to water, encircling the hose, constituting (in the setting position) the lowermost bottom portion 3 which is impermeable to water in the finished bag. The hose is folded so that a sufficiently large bottom is left of its centre part; that is, folding lines L2 of their own are left between the bottom and the front wall and between the bottom and the rear wall, sufficiently spaced so that the bag stays upright. These two folding lines L2 extend inside the water-impermeable area 1 b, wherein a water-impermeable collar is formed for the bottom portion 3, extending a certain length upwards. A corresponding collar is formed at the lower ends of the inner walls left behind the outermost front wall and the outermost rear wall and facing each other.

Between the folding lines L2, the lower surface of the bottom consists totally of the water-impermeable area 1 b. Also, the upper surface of the bottom on the opposite side, left inside the folded hose, consists of the water-impermeable area 3. The package material of the bag can also be sealed totally together in the area between the folding lines L2 before the filling, wherein there is no beverage preparation in the bottom, and the bag 1 is, in a way, a “double bag” or a “double pouch”, in which spaces containing beverage preparation and being totally closed below are formed between both folding lines L2 and the upper end 2 a of the bag. Bags are also known in which the packaging material of the bag is not sealed together between the folding lines L2 but the bag is, in other respects, formed in the same way by an elongated hose-like piece.

The suspension point B determining the draining position is, in the bag of FIG. 1, placed at a point at the edge of the bottom where there is a central fold L3 between the folding lines L2, lifting the bottom slightly upwards at the centre. The suspension points A, B are placed in the same vertical plane that splits the bag into two symmetrical halves and extends between the front and rear walls and at the bottom equidistantly from the folding lines L2, parallel to them. FIG. 1 also shows how the supporting surface impermeable to water does not need to be uniformly against the support 5 but it will suffice that there are supporting points (folds L2) coming against the counter surface, inside which points the mass centre of the bag is located as seen in a horizontal projection.

FIG. 4 shows a blank web which is suitable for manufacturing a bag shown in FIG. 1 in the above described manner. The bags are formed by cutting successive rectangular blanks at cutting lines S from the blank web, which blanks are folded along folding lines L1 to form flat hose-like intermediate forms which are open at both ends. The hoses are folded in the middle, along second folding lines L2 transverse to the preceding folding lines, to form bags. The blank web is made of a material having a filter structure, whose centre part is covered in the direction of the folding lines L2 with a strip of a water-tight material with a certain width, extending in the longitudinal direction of the blank web and constituting the water-impermeable zones 1 b in the blanks separated from the blank web. The second folding lines L2 are left inside the water-impermeable areas so that an edge zone is left between the folding lines L2 and the outer edges of the areas 1 b, said zone constituting a collar extending in the direction of the side walls in the bag.

The material film constituting the water-impermeable zones 1 b may be, for example, plastic. The material may be, for example, a plastic film whose outermost surface is water repellent or treated to be water repellent. The material is attached to the web material having a filter structure by, for example, heat sealing. Packaging materials having a filter structure are also known, which can be subjected to ultrasonic sealing to close the bag, and the water-impermeable material film can also be attached to such a material by ultrasonic sealing.

The material film which forms the water-impermeable areas can be attached to the packaging material having a filter structure over the whole surface or pointwise. The material film can also be off the packaging material at its edges, provided that in the finished bag these edges constitute an upward directed collar which prevents water from leaking.

When the bag is being formed of the blank, the beverage preparation can be fed into the bag when the bag is in the hose-like intermediate form. The material remains inside the bag when the bag is, after the filling, sealed up by seaming the ends of the hose together. If the hose is sealed up in the centre area of the bottom, the beverage preparation is introduced through both of the open ends of the hose before the bag is sealed.

FIG. 5 shows a different kind of a blank web which is used for making bags in the shape of a tetrahedron, and also here the material of the water-tight bottom part 1 a is placed onto the blank web in such a way that when the blanks are cut out and folded, a water-tight bottom portion 3 is formed onto the bottom of the tetrahedron, having a collar extending to a certain height. In the blank, the water-tight area 1 b is formed by a triangular area and a strip with a given height extending to the side therefrom in parallel to the base of the triangle. The bottom is formed in whole inside the triangular part, and the collars are constituted of the areas bordered by the sides of the triangle and of the strip extending to the side. The tip of the triangle is blunt; in other words, the sides of the triangle do not join at the outer edge of the blank. The tip of the triangle also remains incomplete at both edges of the base of the triangle; at one edge it is joined by the strip, and at the other edge, the base and the side of the triangle are bordered by the edge of the blank. The blank is folded in the middle along a first folding line L1 extending in the joining point of the triangle and the strip to form a flat bag, and it is sealed up at the side edges and at the bottom edges limiting the base of the triangle and the strip, after which the beverage preparation can be inserted into the bag through the mouth that is left open. After this, the mouth of the bag is closed by pressing the folds at the ends of the opening against each other, wherein the direction of the mouth is turned to right angles to the original, and one edge of the tetrahedron is formed. In FIG. 5, a broken line outlines the area inside the water-tight zone 1 b, which forms the lowermost bottom, the area left outside this area forming a water-tight collar extending upwards from the plane of the bottom.

FIG. 6 shows a bag for a beverage preparation folded from the blank of FIG. 5. The side wall 2 is formed by three triangular faces of the tetrahedron, extending upwards. The original folding line L1, which extends in the middle of one face, is depicted with a broken line. In this bag, the suspension point A of the setting position is at the upper end 2 a or “vertex” of the tetrahedron, and the suspension point B of the infusing position/draining position is, in turn, located lower at the centre line of one face of the side wall 2 of the tetrahedron, wherein the edge 2 b located directly on the opposite side and extending in the same vertical plane with the centre line, can be directed downwards in the draining position, and water can be drained through this edge. Also in this case, the suspension point B is placed in the water-impermeable area of the bottom portion. Also in this case, the suspension points A and B are joined by a suspension string 4 which is fixed at one end (A) to the vertex of the tetrahedron and at the other end (B) to the material which is impermeable to water.

In principle, a bag functioning in a corresponding manner can be formed to a cube, wherein one face of it forms a supporting surface, whose water-impermeable structure is continuous and extends in the height direction to a part of the area of the four other faces joining to said one face.

The invention is not limited solely to bags with the shape shown in the figures, but it can be applied into bags of varying shapes. FIG. 7 shows a bag 1 whose surface is not polyhedral but curved, for example circular or oval. Also this kind of a bag can be provided with an area which is impermeable to water, forming a supporting surface coming against a counter support in the setting position, and a collar extending upwards from it

If the water-impermeable area 1 b is formed in a blank material having a filter structure, permeable to water, by attaching a water-impermeable material onto it to the extent of said area 1 b, or by performing a coating or surface treatment to the extent of this area 1 b, the blank material having a filter structure can consist of a known material used e.g. in tea bags, such as a loose non-woven or a mesh fabric which has been woven or made in another way. As the package material having a filter structure, it is possible to use, for example, a thin gauze-like non-woven fabric which is food-compatible and is ultrasonically and thermally sealable, marketed by Ahlstrom under the trademark BioWeb and made of polylactic acid (PLA). Also other materials and methods for forming the water-permeable area 1 a and the water-tight area 1 b in the same manufacturing material of the bag are feasible.

If the water-permeable area 1 a of the packaging material is biodegradable, the water-tight area 1 b can also be made biodegradable. If the same packaging material film is used, in which the water-permeable area is formed, this can be achieved by selecting a film made of a biodegradable material. If the water-tight area is formed by adhering a water-tight material piece onto a package material that is already permeable to water (having a filter structure) and biodegradable, this can be done by selecting, for example, a biodegradable plastic. As biodegradable materials, in view of both the water-permeable area and the water-tight area, it is possible to use, for example, a biodegradable plastic, such as polylactic acid (PLA) or some polyhydroxyalcanoate (PHA). PLA and PHA are, as such, hydrophobic, but if one wants to increase the water-repellancy of the outer surface of the water-tight area, this can be done either by coating or another surface treatment technique. The packaging material having a filter structure can also be made of a biodegradable natural fibre, wherein the material piece to be attached as the water-tight area onto it can consist of a biodegradable plastic, for example PLA or PHA. This material piece of a biodegradable plastic can be surface treated by coating or another surface treatment technique.

Furthermore, the aspects of the present disclosure are not limited solely to bags with suspension points to determine the setting position and the draining position, but it can be applied in bags containing a beverage preparation that are designed to be freely placed by hand, wherein they can be “soaked” in a cup or a glass and lifted up with a spoon or with fingers and kept in the draining position and then be placed by fingers or by an appliance to the setting position with the water-impermeable supporting surface against a counter surface.

The water-impermeable structure 1 b which has been added as a separate material piece can be arranged to conform to the flexible packaging material in such a way that it will be located in a suitable place in the bag and will be formed as a water-tight supporting surface and a water-tight collar when the bag is formed, filled with the beverage preparation and sealed, as shown in FIGS. 1 to 7. The water-impermeable structure can also be a rigid “tray” or “trough”, for example of plastic, with an upwards extending collar, wherein it can be fixed in the area of its bottom to a suitable place in the package material in such a way that it forms a corresponding water-impermeable structure with corresponding functions in the finished bag.

In the packaging material enclosing the beverage preparation, the surface area of the water-permeable area is preferably larger than that of the water-impermeable area. The ratio of the areas is advantageously greater than 3, more advantageously greater than 5.

The bags can be packed one by one in single protective packages in the same way as tea bags, or several bags can be packed at a time in a larger package. 

1. A bag for a beverage preparation, comprising: a disposable closed bag formed of a package material defining an interior of the closed bag, a beverage preparation of a solid substance placed in the interior of the closed bag, said substance being capable of giving off components of the beverage through a water-permeable portion of the package material when the bag is infused in water for preparing a beverage, and a supporting surface which forms a portion of the package material and which is formed as a water-impermeable structure having an upward dimension as a collar of a given height, for preventing water from leaking out from a wetted beverage preparation in the interior of the closed bag.
 2. The bag according to claim 1, wherein the bag comprises a bottom portion formed as a water-impermeable structure, side wall (2) of the bag permeable to water above the bottom portion, and a water-impermeable area of the bottom portion extending as a collar to a given height in the direction of the side wall.
 3. The bag according to claim 1, wherein the bag comprises two suspension points which define two different inclination positions for the bag, wherein the first suspension point determines a setting position, in which the bag is suspended with the supporting surface facing downwards, and the second suspension point determines a draining position, in which the supporting surface is turned to an angle to the setting position.
 4. The bag according to claim 3, wherein the suspension points are connected by means of a suspension string.
 5. The bag according to claim 3, wherein the second suspension point defines a position, in which an edge on opposite side of the bag with respect to the location of the second suspension point is directed downwards.
 6. The bag according to claim 3, wherein the second suspension point is placed in the water-impermeable structure.
 7. The bag according to claim 3, wherein in the draining position of the bag the side wall of the bag above the bottom portion of the bag is turned to a smaller angle to the horizontal plane than in the setting position. 